Not Applicable.
Not Applicable.
1. Field of the Invention
The present invention generally relates to photonics and, more particularly, to apparatuses and methods for measuring cross-sectional areas of objects.
2. Description of the Related Art
In many businesses, the cross-sectional area of an object must be measured and recorded during the course of normal operations of the business. For example, in the nursery business growers of shade trees are periodically required to determine and record information about each tree on their grounds. Information which is critical to the efficient operation of the nursery includes, for example, the diameter of the tree, the exact location of the tree on the grounds, and the grade or quality of the tree. The need for speed and accuracy in determining and recording the information is of vital importance to the economic success of the nursery. The gathered information is typically maintained in a computerized inventory system which is consulted by nursery managers when filling orders and estimating future tree stock.
In the inventory process used by many nurseries, a field worker must determine the location of a given tree, grade the tree, measure the tree, and hand transcribe the information into a paper logbook. Many nurseries perform the measuring operation with a measurement device that uses a flat metal template with notches of varying width to approximate the diameter of the tree. The diameter of the tree is considered to be equal to the narrowest set of notches on the template between which the tree fits. Although the trunk size of commercial trees range in size from less than one inch in diameter to greater than ten inches in diameter, a typical nursery is interested in a range of diameters from 0.5 to 3.5 inches. For this range of trunk diameters, a measurement error of less than 0.25 inch is desired. As tree trunk cross sections are usually more oblong than circular, the use of a notched template will yield different tree diameters when measured from different directions. Also, the naturally rough tree bark surface makes consistent fitting of the notched template difficult. These problems all result in inconsistent tree measurements that change with the operator performing the measurement. In addition, the transcription of information into a logbook and the subsequent manual entry into a computerized inventory system is time consuming, expensive, and prone to errors.
Alternatively, some tree growers perform the measuring operation with a device that utilizes a mechanical caliper that is attached to an onboard processor. The diameter of the tree is calculated based on the position of the calipers in contact with the tree. Given the diameter of the tree, the cross-sectional area may be approximated by assuming the tree is circular in shape. The onboard processor also permits entry of data such as the location and quality grade of the tree. The data may then be downloaded from the onboard processor to an inventory management computer of the nursery. Thus, although this device eliminates some of the potential errors associated with the manual transcription of data, the device is expensive and the accuracy of the device is limited to measuring only circular cross-sections of objects.
Accordingly, there exists a need for an accurate and cost effective manner to determine the cross-sectional area of an object.
The present invention is directed to an apparatus for determining a cross-sectional area of an object. According to one embodiment, the apparatus includes a plurality of radiant energy sources, a plurality of radiant energy detectors oriented to receive radiant energy emitted by the plurality of radiant energy sources, a strobing module in communication with the plurality of radiant energy sources for strobing the plurality of light sources, and a profile determination module in communication with the plurality of radiant energy sources and the strobing module for determining the cross-sectional area of an object disposed between the plurality of radiant energy sources and the plurality of radiant energy detectors.
According to another embodiment, the present invention is directed to an apparatus for determining a cross-sectional area of an object that engages both sides of a V-shaped opening, including a range finder located a known distance from a vertex of the V-shaped opening, and a profile determination module in communication with the range finder.
The present invention represents an advancement over prior methods and apparatuses used to determine the cross-sectional area of an object, such as a tree trunk, in that it is more accurate due to the fact that the object does not have to be assumed to be circular in shape. In addition, the present invention represents an advancement in that it is efficient and relatively inexpensive. These and other benefits of the present invention will be apparent from the detailed description hereinbelow.